Armature for dynamo-electric machines



(No Model.)

L. DAPT. ARMATURE FOR DYNAMO ELECTRIC MACHINES.

No. 393,745. Patented Dec. 4, 1888.

Il HII'IJHL ru. i

l i 44W l' L -Y `Hillilllllllllllll Effed l Inval-Liar; g

afin y I UNITED STATES PATENT OEEtcE.

lili() DAF'l, (')F PLAIFIELD, NEW JERSEYf ARMATURE FOR DYNAMO-ELECTRIC MACHlNES.

SPECIFICATION forming part of Letters Patent No. 393,745, dated December 4, 1888.

Application led September 14, 1835. Renewed May 4, 1888. Serial No. 272,856y l'No modela To all whom it may concern: f Be it known. that- I, LEO DAFT, a subject of the Queen of Great Britain, residingl at Plaini tield, in the county of Union and State 0f New Jersey, have invented certain new and useful Improvements in Armatures, ot' which the following is a specification.

My invention relates to dynamo andv magg neto electric generators or motors; and it has for its object to improve the construction of g the armature-cores of such machines, so as to lrender them mechanically strong and firm, and to provide them with a sufficient mass of solid material for the proper and rigid attachment of the supporting spider-arms, and at the same time to avoid the use of large masses of magnetic material in the ends of the core. l

To these ends my invention consists of a l core for electric generators or motors, constructed substantially` as more particularly pointed out hereinafter.

Referring to the accompanying drawings, l'igure l is a side view of an armaturecore orso much thereof as embraces my present invention. Fig. 2 is an end view thereof. g

lt is a well-known fact that the presence of large masses of magnetic material in the cores of armatures for electric generators and motors is objectionable, as they tend to weaken the effect of such machines by the formation of eddy-currents or so-called Foucault currents, which occasion considerable loss of power as well as destructive heating of the core. lli any means and devices have been proposed for obviating these objections-as tor instance, forming the body of the core of i soft-iron wire, cutting slots in the body of the core, makingI it of thin plates or laminae of iron, alternating with disks of paper, liber, or other insulating material, so arranged as to diminish the eddy-currents in the body of the armature-core. In many cases the ends of the core have been formed, however,with comi paratively large masses of magnetic material, l in order that the core could be suitably supported or held in place; or when these have been omitted it has been found diicult to torm a tlrm and strong mechanical connection with the body otl the core, so that it may be rapidi y rotated under the influence ot' powerful currents without derangement.

lt is the objectot my invention to overcome these objections, and in doing so l make use of any of the well-known forms of corebody-as, for instance, the alternating plates l) of the spiders ortrames i3.

of magnetic and insulating material. 'lo this body I secure the rings A A, the thickness thereof being shown in dotted lines, Fig. 2, and which are made of a size to be suttieiently strong to properly secure and hold the body ot' the core and to receive the extended arms These rings are made ot' some diamagnetic material, as phosplier-bronze, which is not subject to the magnetic int'luences, and thus while they t'orm good mechanical supports and holders for the core they do not interfere with the magnetic action thereotl or become heated under the iu- [luence of the eddy-currents.

The spiders B are formed with substantial bearings adapted to tit the sha t't of the armature and to be secured thereto in any ordinary manner, as by screws, as shown, andthe arms l) are bent at an angle and tit into slots or recesses a in the periphery ot the rin A, and are there secured by suitable means, as by screws or rivets s.

It will thus be seen that not only is the body of the core freed from the ob jectionable feature, but the large and tirm rings which are necessary tohold it are also free from the mae'- netic action, and the spider-arms are securely connected to the rings in a thoroughly mechanical manner; and I have found that armature-cores so (fonstrtu-ted are well adaptml for continued use under severe conditions.

It apparent that the t'orm ot' the rings` may be varied to suit the particular construction of the core-body without delliiarting from the spirit of my invention.

lVhat l claim isl. In an electric motor or generator, the combination, with the body ot' the core, ot` a ring of phosphor-linonze to which the core is attached, and spider-arms having laterallyprojecting ends embr-wingI the rin substantialiy as described.

The combination, in an electric motor or generator, of the spider having arms bent a t. an angle, with the ring ot' diamagnetic material having recesses into which the arms are secured, substantially as described.

In testimony whereotfl have signed my name to this specification in the presence ot' t wo sul scrihing witnesses.

LE() DAFT.

Witnesses:

JNO. N. Beans, FRED H. REED.

IOO 

